A sleep regression is a temporary period when a baby who was sleeping well suddenly has disrupted sleep. Your baby may wake more often at night, struggle to fall asleep or fight naps. This is usually not a problem but a sign of development. Brain development, new motor skills such as rolling and crawling, teething and separation anxiety can all affect sleep for a while.
The most talked-about periods are 4, 6, 8 to 10, 12, 18 and 24 months. The 4-month regression is the best known, because at this age a baby's sleep cycles start to look more like an adult's and sleep gets lighter. Each regression usually lasts 2 to 6 weeks. Not every baby goes through every regression, and some pass very mildly. For premature babies, these periods are expected by corrected age.
What helps most during this time is consistency. Keeping the same bedtime routine, staying calm and offering closeness help the phase pass more easily. Before starting new habits, it helps to remember that the phase is temporary. If the sleep problem lasts longer than 4 weeks, or comes with symptoms such as fever or ear pain, the cause may not be a regression.
What you can do
- Shows whether a regression may be active right now for your baby's age.
- See which week of an active regression you're in.
- Tells you how many weeks until the next regression starts.
- Signs, cause and parent strategies for each of the 6 regressions.
- For premature babies, corrected age is used.
- Get 3 practical AI suggestions for the current phase.
How to use it
- Make sure your baby's birth date is saved in your profile.
- See your baby's current phase on the active regression card.
- Read the signs, cause and strategies.
- Get through the phase calmly with a consistent routine.
Frequently asked questions
How long do sleep regressions last?
A sleep regression usually lasts weeks, not months. Most settle within 2 to 6 weeks. The length depends on the baby and the development behind it. Keeping the routine consistent helps the phase pass faster and more easily. If the sleep problem lasts more than 4 weeks or comes with other symptoms, it's a good idea to talk to your doctor.
What is the 4-month sleep regression?
The 4-month sleep regression is a disruption in sleep seen around 3 to 4 months. At this age, a baby's sleep cycles change for good and start to look more like an adult's. Sleep gets lighter, and your baby wakes more easily between cycles. That's why, unlike the others, the 4-month regression is a shift to a new sleep pattern. Learning to fall asleep on their own helps during this time.
How do I know if my baby is going through a sleep regression?
Signs include a baby who slept well suddenly waking often at night, struggling to fall asleep, fighting naps and being fussier. This change often lines up with a new skill such as rolling or crawling. If there are signs of fever, pain or illness, the cause may not be a regression, so talk to your doctor.
How do you survive a sleep regression?
Keep the same routine every evening, such as bath, lullaby and a dark room. Stay calm, because your calm rubs off on your baby. Skin-to-skin contact and cuddles soothe your baby. Try not to let your baby get overtired, and don't skip naps. Before starting lasting new habits, remember that the phase is temporary. Always follow safe sleep rules.